Peel and cube the potatoes, place in a large pot with salted water, bring to a boil, and cook for about 15 minutes or until fork-tender. Drain and return to warm pot to steam off excess moisture before mashing.

Add butter and warmed milk to the drained potatoes and mash until smooth with no lumps. Season with salt to taste, then cover to keep warm.

In a large skillet, heat olive oil over medium-high heat. Season shrimp with paprika, garlic powder, salt, and pepper. Add shrimp to the skillet and sauté for 2-3 minutes per side until pink and opaque. Remove shrimp from the skillet and set aside.

In the same skillet, lower the heat, melt butter, and sauté minced garlic until fragrant. Pour in heavy cream, stirring, and allow to simmer. Gradually whisk in Parmesan cheese and optional Dijon mustard, letting sauce thicken for 3-5 minutes.

Serve by spooning mashed potatoes onto plates, topping with shrimp, and drizzling with sauce. Garnish with fresh thyme.